| 摘要 |
PURPOSE:To reduce cost while minimizing reflection loss, and to improve efficiency by forming a buffer layer and a GaAs layer onto an Si substrate, on the surface side thereof irregularities consisting of mutually adjacent fine tetrahedrons are shaped, and forming the irregularities of the mutually adjacent fine tetrahedrons to the surface. CONSTITUTION:Irregularities composed of fine tetrahedrons are shaped uniformly on the surface of an Si substrate 14 through a selective etching method, and a buffer layer 13 is evaporated onto the surfaces of the irregularities under vacuum. An N-GaAs layer 12, a P-GaAs layer 11 and a P-GaAlAs layer 10 are grown on the buffer layer 13 with the irregularities in an epitaxial manner, surface electrodes 15 are shaped onto the P-GaAs layer 11 and a back electrode 16 onto the back of the Si substrate 14, and an antireflection film 9 is formed. Accordingly, since a surface shape has the irregularities composed of the mutually adjacent fine tetrahedrons, reflectivity on the surface can be reduced as a whole by the multiple reflection of incident beams to each surface, thus improving conversion efficiency. |
